643644080 has 40 divisors (see below), whose sum is σ = 1499790912. Its totient is φ = 256886784.

The previous prime is 643644061. The next prime is 643644097. The reversal of 643644080 is 80446346.

It is a happy number.

643644080 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 643644080.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28352 + ... + 45728.

Almost surely, 2^643644080 is an apocalyptic number.

It is an amenable number.

643644080 is an abundant number, since it is smaller than the sum of its proper divisors (856146832).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643644080 is a wasteful number, since it uses less digits than its factorization.

643644080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17853 (or 17847 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 35.

The square root of 643644080 is about 25370.1415053208. The cubic root of 643644080 is about 863.4063923835.

The spelling of 643644080 in words is "six hundred forty-three million, six hundred forty-four thousand, eighty".